-. (1989). Nature's wonderlands: National park of the world. National geography society.
शिकागो शैली (17वां संस्करण) प्रशस्ति पत्र-. Nature's Wonderlands: National Park of the World. Washington: National geography society, 1989.
एमएलए (9वां संस्करण) प्रशस्ति पत्र-. Nature's Wonderlands: National Park of the World. National geography society, 1989.
चेतावनी: ये उद्धरण हमेशा 100% सटीक नहीं हो सकते हैं.